Refrigerating machine



Dec. 14, 1937.

H, H. BlxLl-:R

REFRIGERATING MACHINE Filed Jan. ll, 1935 2 Sheets-Sheet 2 Inventor:Hawlefg H. Bixler,

' Attof'ny .i

2,ll2,43 REFREGEEEATHNG MACHEN@ Harley itl. Binler, Schenectady, N.,Yaassignor to General Electric @ompm la comoration oi New crisApplication January lli, i935. Serial No. L33? Refrigerating machines ofthe compression type y include a compressor for compressing a gaseousrefrigerant, the compressor being driven by an electric motor or thelike. The gaseous rerigerant so compressed is cooled and liqueiied in asuit= able condenser from which it flows to an evapora-1 tor or othercooling unit. The liquid refrigerant is caused to boil in the coolingunit by the absorption of heat from surrounding objects. `The gaseousrefrigerant thus formed by the boiling in the cooling unit is returnedto the compressor and the cycle is repeated. In operating machines ofthe type described, it is desirable to provide some mechanism forunloading the compressor during the starting period in order that themotor may start under a comparatively light load and .hence not draw anexcessive starting current. lt is also desirable that the unloadingmechanism should. be arranged to unload the compressor when the supplyof current to the motor has been shut oli" and the motor is coasting toa stop inorder to minimize vibration of the machine.

In addition I have found it desirable to arrange the unloading mechanismin'such a manner that the compressor will be unloaded when the amount oflubricantsupplied to the bearings of the ma= chine is'insuicient inorder that. damage, result-1 ing from running the parts fully loadedwhen they are not properly lubricated, may be avoided. This problem isof particular importance in the case of closed compression systemrerigerating machines in which the compression system con:- tainslubricant such as oil. In such machines the lubricant is mingled withthe refrigerant during at least a part of the operating cycle and if thelubricant is not thoroughly purged of gaseous reirigerant before it issupplied to the parts which it is intended to lubricate it may be sothinned by vthe refrigerant that improper lubrication will he had.

it is .an object of my Iinvention to provide an improved unloadingmechanism for refrigerant compressors or the like.

It is a further object of my invention to prende a compression typerefrigerating machine or the like including apparatus for unloading thecompressor thereof when an insullcientamount or" lubricant is suppliedto lubricate said machine.

Another object 'of my invention is to provide a compressiontyperefrigerating machine or theN like including apparatus for unloading thecornpressor thereof when the lubricant supplied therea to contains toolarge a percentage or reirigeran therein to insure adequate lubricationoi said machine.

.Anotherobject of my invention is to provide an improved refrigeratingmachine of the type de-z scribed which vvill be ecient in operation andin which any noise caused by its operation is minimized.

Further objects and advantages of my invention will become apparent asthe following description proceeds and the features ci novelty whichcharacterize my invention will be pointed out with particularity in theclaimsannexedto and forming a part of this specification.

' For a better understanding of my invention, reference may he had tothe accompanying drawings, in which Fig'. l is a side elevation, partlyin section, of a reirigerating machine embodying my invention; Fig. 2 isa plan view o; the casing andA motor driven compressor included in therefriger-L ating machine shovvn in Fig. l the top of the com.'- pressorand part of the top of the motor being broken away; Fig. 3 is a planview of the rotary lubricant pump on the line 3 3 of Fig. 5; Fig. i ls apartial bottom plan view of the Scotch yoke mechanism of the compressorshown in Fig. l; Fig. 5 is a side elevation partly in section along' theline 5 5, of the apparatus shown in Fig. 2;

Fig. 6 is a fragmentary sectional view of the valve and unloadermechanisms included in the refrigerating machine shown in Fig. l; Fig. 7is a detail view of a valve assembly for the compressor in-s cluded inthe reirigerating machine shown in Fig. 1;iiig. 8 is a sectional viewalong the line 8-8' of the relief valve included in the valve assemblyshown in Fig. 7, and Fig. 9 is a iragmentaryenlarged longitudinalsectional view of the unloader cylinder. y

Referring to the drawings, in Fig. i I have shown a refrigeratingmachine provided with an hermetically sealed casing I made up of anupper casing section 11i and a lower casing section i2, the adjacentedges of these sections being Welded together over a reinforcing ring I3as indicated at'lll. The casing sections liland i2 are preferably madeof steel, and mounted on a rel movable cabinet top ige. A refrigerantcompresser l and an electric driving motor I6 therefor are containedWithin the hermetically sealed casing lo. The compressor I5 is securedto the top of the driving motor I6 by bolts I1 and i8, thus forming acompact unitary structure. This unitary structure is mounted in thecasing ,i0 on three vertical helical springs I9, 2|), and 2l. The upperends oi' springs iii, 2S, and 2l are secured to Fleet 22, 23, and "63,respectively, these feet being welded to the periphery of the frame ofthe motor I 6 at equally spaced intervals of approximatevns ly 120. Thelower end of the spring 20 is supported on an indentation 25 formed inthe lower section I2 of the casing I0, as shown in Fig. 5. The springsI9 and 2l are also supported on similar indentations formed in the lowersection I2 of the casing I0. A bumper ring 26 surrounds the unitarystructure and is secured in a slot 21 in a foot 23, as illustrated inFig. 5. Similar slots are formed in the feet 22 and 24 for supportingthe bumper ring 26. 'A series of stops 26, 29, and 30 are welded to theinner side wall of the casing I at spaced intervals of approximately 120as best shown in Fig. 2. These stops limit the vertical movement of theunitary structure by engagement with the bumper ring 26.

in slots therein in the usual manner. End shields and 36 are providedfor the upper and lower ends, respectively, of the stator 33, beingsecured thereto by bolts 31. The shaft 32 is supported in upper andlower bearings 38 and39, ,respectively. The upper bearing 33 is of theself-aiming sleeve type, having a relatively large axial length -ascompared to its'diameter and is loosely mounted in a cylindrical boreformed in the upper end shield 35 and preferably having a-sucklng Vilttherewith. Rotation of the bearing 36, in bore 40 is prevented by a pin38a. The lower bearing 39 is a machined surface of a cylindrical bore'formed in the lower end shield 36 in axial alinement with the shaft 32.Since the compressor I5 is located closely adjacent the upper bearing33, most of the lateral thrust on the shaft 32 is takenup by this upperbearing and the lower bearing-33 may consequently be relatively short ascompared to its diameter and hence need not be of the selfA-aliningtype. The lower end of the shaft 32 is supported on a retaining plate 4Iwhich is secured to the lower end shield 36 by bolts 42, which'are in`threaded engagement with tapped holes 43 providedin the lowerv endshield 36. The upper surface of theretaining plate 4I is ground toprovide a vsmooth flat surface on which' the end of the shaft 32 mayfreely rotate. Any down- Y ward axialthrust on the shaft 32 is thustaken up bythe retaining plate 4I. By the use of such a bearingarrangement contained within the end shields 35 and 36, a compactstructure having a minimum vertical height is provided.

The lupper end of the shaft 32 is -provided with `a crank arm 44 and alcounterweight 45'. The

compressor I5' is of the Scotch yoke type and includes a cylindricalslide 46, and during reciprocation of a piston'49 by the crank 44 theslide is reciprocated in a cross-head 41, the crank 44' passing throughan elongated slot or opening 43 in the lower side of the cross-head 41.The piston 4s is welded to the cross-head 41 and is reciprocated in abore 53 of a compression cylinder 5l. The rotary movement of the crank44 causes a reciprocatory movement of the slide 46 in the vcross-head41, and a reciprocatory movement of the piston 49 in the bore 50 of thecompressor cylinder 5l.

The particular construction of the piston and yoke illustrated is not myinvention, but is the invention of Christian Steenstrup, and isdescribed and claimed in his application, Serial No. 12,390, iiledMarch,22, 1935, and assigned to the General Electric Company, theassignee of my present invention.

One end of the bore 50 of the compression cylinder 5I is closed by a.fiat valve plate 52, which is secured to the cylinder 5I by bolts 53.The bolts 53 also hold a muille box 54 in 1:lace` on top of the valve`plate 52. As best shown in Fig. '7, the valve plate 52 is provided witha relatively largeintake opening 55, which is closed by a ilexible inletvalve 55a. The inlet valve 55a is preferably made'in the form of atongue which is an integral part of a thin plate of steel or thellke 55hhaving the same peripheral dimensions as the valve plate 52 and havingan opening 55o. A series of relatively small exhaust ports 56 arrangedin a circle are also provided in the valve plate 52 and are normallyclosed by a disk-shaped flexible exhaust valve 56a. The exhaust valve56a is provided with a disk-shaped retainer 56h, the retainer 56h andexhaust valve 56a being secured to the valve plate. 52 by a rivet .51which passes through registering central apertures in 4the retainer andexhaust valve. The valve plate 52 is also provided with a relief port58, which is closed by a relief valve 59. The relief valve 59 isnormally biased to the closed position by a helical compression spring60 which urges a stud 6I against the valve 59. The tension of the spring60 i`s so proportioned that if the pressure in the cylinder bore 50exceeds a predetermined safe value, because of the failure of theexhaust valve 56a to opener for some other reason, the valve 59 willopen and bleed `a portion of the compressedl fluid in the cylinder bore50 into the interior of the casing I0. y

The general arrangement of the valve assembly described above forms nopart of my present invention, but is described'and claimed inmyapplication Serial No. 26,067, filed June, 11, 1935, and

assigned to the General Electric Company, thel assignee of my presentinvention.-

A body of oil or other `lubricant 62 is maintained in a reservoir,formed in the lower sectionq I2 ofthe casing |021 Lubricant iscontinuously through a conduit 63 by a rotary pump 64, which isv drivenby the shaft 32 of the motorl6. As best shown in Fig. 3, the rotary pump64 includes a pair of oppositely extendingv blades 65 and 66, which areslidably mounted Iin slots 61 and 63,

, respectively, formed in the lower end of the shaft 32. The. lower endof the shaft 3,2 and 'the blades 65 and 66 rotate in a chamber formed bya cylindrical bore 69 in a casing plate 16, the center of the bore 69being eccentric with respect to the center of the shaft .32. Theretaining plate 4I andy a cover plate 1| are secured to the lower Linalcance side of the casing plate i8. The coverplate ill, the retainingplate il and the casing l1@- are held in their assembled position by thebolts d2. As the blades 65 and 86 rotate in the chamber 89, in aclockwise direction, for example, as viewed in Fig. 3, lubricant isdrawn into the chamber 89l through the conduit 83 and an intake openingl2 .formed in the retaining plate @lli due to the increasing volume ofthe space behind the blade 85. Upon further rotation of the shaft 32,the lubricant is expelled under Ypressure from the chamber 89 through anoutlet opening 'i3 formed in the retaining plate 4l.; This pumpingaction is due to the decreasing volume of the space in front of theblade 56 y.as the rotation of the shaft 32 continues. The blades 85 and88 are pushed outwardly against the wall of the chamber 89 bycentrifugal force and by the pressure of the lubricant in passage l5.Lubricant discharged through an outlet opening 13 in the retaining plate4l passes into a depression 'I4 formed in the cover plate ll -and thenupwardly through the central axially extending passage 'I5 formed in theshaft 32 of the motor i6. A portion of the lubricant passing upwardlythrough the passage l5, flows through a passage 16 which communicateswith the lower portion o f the pass-age l5, and passes through thepassage 'I6 to a groove l? ormedin theY lower bearing 39 of the shaft 32thus lubricating the bearing 39. A horizontal passage 'i8 communicatingwith the upper portion of the passage l is also formed in the shaft 32and communicates with a circular groove 'i9 formed in the upper bearing38. Lubricant for`the bearing 38 is supplied thereto from the passage l5through the passage 'i8 and groove 19. The surfaces of the bearings 38and 3'9 may be pro# vided 'with` cross grooves communicating with thegrooves 'il and 19 in order to more thoroughly distribute the lubricantover the surface of the bearings. A further portion of the lubricantunder pressure in the passage 'I5 passes upwardly therefrom through apassage 80 formed inthe crank 44 to the top of the latter and lubricatesthe contacting surfaces of the crank 44 and the slide 46, as well as thecontacting surface of the cross-head 4l.- A second passage 8| is alsoformed in. the crank 44`in order to allow lubricant to pass downwardlyfrom the top of the crank 44 to the contacting-surfaces of the slide 46and the crank 44 in orderto insure thorough lubrication of the same. Apassage 82 is provided in the upper end shield of the. motor I6 whichcommunicates with the groove 79 formed in the upper bearing 38 andsupplies lubricant under pressure there-V from to an unloader 83. Thepassage 82 communicates at its upper end with a bore 84 of an unloadercylinder 85 of the unloader 83. In theA illustrative form of myinvention, the compressor cylinder 5l and unloader cylinder 85 are madeas an integral structure, the bores 50 and 84, respectively, of thecylinders being arranged inv parallel relationship. The unloader 83includes* a cupshaped piston 86 vwhich is provided with a cylindricalsleeve 8l, the piston and sleeve being brazed cr other. ise securedtogether. The piston 8G and sleeve 3l constitute a movablev Wall of thecylinder 85. One end of a U-shapedoperating compressor i5. rThe piston88 is provided with a depression 92 which engages a complementary notchformed in the disk 8 9 thereby preventing rotation of the disk in thepiston 88.

A part of the lubricant supplied under pressure to the bore 89 throughthe passage 82 passes therefrom through a sharp edged orice 94 in thesleeve 8T! to a passage 95. TheA lubricant in the passage 95 hows into apassage so as to lubri cate the piston i9 of the compressor i5, as isdescribed more in detail below. it will be seen that even when theunloader piston 98 is in its retracted position and the compressor i5 isun loaded that lubricant is supplied to the contact- .ing movingsurfaces of the' piston and cylinder of the compressor through the sharpedged orice 99. By a'sharp edged orifice I mean an orice havingv alength which is small compared with its diameter, having a comparativelyabrupt entrance on the upstream side thereof, and providing for apredetermined flow of fluid there,

through substantially irrespective of the viscosity ofQthe fluid iiowingthrough the orice. advantageous to use a sharp edged orifice to die verta portion of the lubricant from the unloader y bore 84, since the amountof uid passing through isdiverted from thebore 84 through the orifice 9avaries directly asthe square root of the pressure. Hence, the area ofthe orifice 94 is preferably so proportioned that it will divert all ofthe'lubricantsupplied to the unloader-83 until the motor i8 reaches apredetermined speed, about 60% full running speed. After the motor l@reaches such predetermined speed the lubricant in excess of the amountwhich may be diverted through the orifice 94 is accumulated in the bore84 and causes the piston 86 to move outwardly. The operating rod 88 isthereby caused to disengage the inlet valve 55a and the latter thenbeing free to^operate normally. As a consequence, the compressor l5 mayat that time begin to compress gaseous refrigerant and the motor i6 willbe loaded. Since the loading ofv the motor i8 is prevented until itreaches a predetermined speed, the danger of its drawing an excessivecurrent at its starting is obviated. As was pointed out above, thequantity of lubricant flowing through the orice 94 is not aifected byviscosity so the motor I6 will always be loaded -at the same speedregardless of the temperature and hence viscosity of the lubricant. Theorifice 9i is so positioned in the sleeve 81 with respect to the passage95 that it registers with the latter when the sleeve 81 is at theextremity of its travel to the right, as viewed in Fig. 2 and Fig. 6,

and is also so positioned that when the sleeve 81 travels to the leftthe orifice 94 will not be cov- Itis"` ered by the wall ofthe cylinder85 until the end of the passage 95 is uncoveredby the end of the sleeve877. Such uncovering of the end of the passage 95 by the sleeve 8lpermits an increased lquantity of lubricant to escape from the cylinderbore 815. The consequent reduction in pressure in the bore i3d limitsthe outward movement of the piston 86 so that the oriiice 94 is nevercovered by the cylinder wall 85 during the normal operation of themachine. Since the bore 84 of the unloader 83 is continuously incommunica.- tion with the passage 95 irrespective of the position of thesleeve `81 and piston 86, lubricant may be continually supplied theretoat all times when the pump 64 is in operation.

'I'he unloader 83 also serves to unload the compressor I5 after theelectrical circuit of the motor `|6 has been opened and the motor iscoasting to a stop. If the compressor I6 were not unloaded during thecoasting period the load imposed on the rotor 3| of the motor I6 bythecompressor I5 would cause the rotor to stop suddenly when the powerwas cut olf, jarring the machine. In the operationof the machine which Ihave illustrated, however, when the motor I6 slows down to apredetermined minimum speed, about of full speed, either because the'power thereto` has been cut off, or for any other reason, the pump 64will also slow down thus reducing the pressure of the lubricant suppliedto the unloader 83. Since the pressure on the piston 86 is thus reduced,the biasing spring 98 will cause the operating rod 88 to engage theinlet valve 56 thus unloading the compressor I5.

`It is particularly advantageous to locate the unloader 83 directly inthe series lubricant 'circuit, so that the lubricant passes' in seriesthrough the principal bearing 38 of the motor. I6', the unloader 83 andabout the piston of the compressor I5. When so arranged, the unloader 88will `thus unload the compressor if an insufficient quantity oflubricant issupplied to the bearing 38 and thepiston 48 to insure thesafe operation thereof. I have accomplished this result in the machineillustrated by providing the sharp edged orifice 84 in the sleeve81,'as` described above, in order that the lubricant in the serieslubricant circuit will pass continuously through the bore 84 of theunloader irrespective of the position of the unloader piston 86 andconsequently the unloader 83 does not at any time stop the iiow oflubricant in the series lubricant circuit. 'I'here is some danger thatgaseous refrigerant may be trapped as in solution in the lubricant whichis pumped to the contacting moving surfaces of the compressor I5 and themotor I6 especially in a closed compression system of the typeillustrated. The lubricant and gaseous refrigerant are in direct contactin the casing I8, so' that refrigerant gas may go into solution in thelubricant, and some of the lubricant may enter the compressor cylinder5I and be circulated vwith thecompressed refrigerant. If thelubricant ispumped to a closed unloader cylinder and only diverted therefrom whenthe unloader piston is in a position to load the compressor there wouldbe danger of loading the compressor when the lubricant contained such alarge quantity of refrigerant that insuiiicient lubrication of thebearings and the like' would be had. In the arrangement which Iprovide', this danger is obviated since the bore 84 of the unloader islin constant communication with its outlet port 85 and 'any y gaseousrefrigerant which enters the bore 85 will be forced on out into thepassage 85, and can not accumulate. in the bore 84 to move the un,-

loader piston 88 to the unloading position.

Lubricant diverted from the unloader bore 84 through the outlet portenters an annular groove formed in 'the wall of the compression Asmaller cooperating annular- 81 registers with the groove 86 when thepiston 48 is in its extreme retracted position shown in Fig. 5. When inthis position, lubricant ows into the groove 91 from the groove 86. Atthe same time, the refrigerant Ain the `cylinder bore 58 is not undercompression and hence there is little or no tendency for it to leak pastthe piston 49. As the piston 49 is moved .to the left, the yrefrigerantin .the cylinder bore n58 is compressed and at the same time the 'groove91 moves out of register with the groove 96. The conrpressed gaseousrefrigerant in thecylinder bore 58 tends to leak between the piston 49and the surrounding wall of the cylinder 5I. 'This leaking refrigerantenters the groove 9,1, however, and displaces a portion of the lubricanttherefrom. This displaced lubricant is forced into' the small clearancespace between the piston 49 and the wall of the cylinder 5I and forms aseal, thus effectually preventing the escape of compressed refrigerantfrom the cylinder bore 58 without the necessity of providing packingrings or the like on the piston 48. When the piston 48 is again moved toits retracted position, the groove 81 comes into register withv thegroove 96 and since the lubricant is being rapidly circulated ythroughthe groove 96, any gaseous refrigerant which is entrapped in -the groove81 is carried away by a. stream of lubricant and later returned to themain body of gaseous refrigerant as is explained below. This arrangementalso effectually lubricates the contacting surfaces 'of the piston 49and the cylinder 5|. Lubricant in the groove 86 is forced upwardltherefrom through an L-shaped conduit 88 which communicates with theupper side of the groove 96, the outer end 89 of the conduit 98 beingclosed. A small hole |88 is provided in the side of the conduit 88 andallows a portion of the lubricant in the conduit 98 to pass .therefrominto a recess I8I formed in the top of the compressor I5. The recess I8Iis covered by a plate |82 which is secured to the compressor by a screw|83. Lubricant passing through the recess I8I drains down across thevalved endof the compressor I5 into a cup |84 which is secured to theside of the motor I6.

'I'he main portion of the lubricant in the conduit 88 passes upwardlytherethrough and is discharged therefrom through a vertically extendingnozzle |85. The lubricant Idischarged from the nozzle |85 passes throughan aperture |86 formed in a horizontal baille |81. which is supported onstuds |88 and |88, the studs beingwelded, or otherwise secured, to thetop of the casing I8.

An outwardly extending recess II8 is provided in the top of the casingI8 opposite the nozzle 85 and serves to distribute the lubricantdischarged from the nozzle |85 evenly over the inner surface of the topof the casing I8; 'Ihe lubricant thus distributed flows through notchesIII provided about the periphery of the horizontal baille |81 and drainsdown the vertical side walls of the casing I8' to; the reservoir formedin the bottom thereof. Since the exterior of the casing 8 is in contactwith a body of cooling air, the lubricant passing over the inner surfaceof the casing I8 is' cooled thereby.I An annulus of fins I I2 surroundsthecasing I8 and aid in the dissipation of heat therefrom.

N 'Ihe lubricant which collects in the cup. |84 ilows therefrom throughan aperture I|8 into an annular chamber |I4 formed between the top ofthe stator 88 and the end shield 35. 'I'he lubricant thus corrected 1nthe chamber m news2 lll downwardly through the slots Sila in which theenergizing windings till are located and absorbs heat therefrom. After'draining through the slots 34a in the stator the lubricant is collectedin a reservoir ll provided in the lower end shield where it surroundsthe lower ends ol the energizing windings Sil. Lubricant supplied to thetop of the cranl; ld flows downwardly over the right hand side of themotor [It into a cup lili, which communicates with the reservoir lib.The lubricant accumulated in the reservoir M5 ows therefrom through anaperture (not shown) provided adjacent one of the helical supportingsprings lll. The lubricant directed on to the supporting spring l@ flowsdown the same and into the body of lubricant G2 in the reservoir formedin the lower section l2 of the casing ld.

The lubricating system and lubricant cooling system described above arenot my invention, but are the invention o Christian Steenstrup and aredescribed and claimed in his application Serial No. 1,319, filed Januaryl1, 1935, and assigned to the General Electric Company, the assignee ofmy present invention.

In the operation of the reirigerating machine described above, gaseousrefrigerant in the casing lll, which is at the low pressure existing inthe evaporator t28, enters an intake muffler lll, passes through avconduit llt to a lchamber ll@ formed in the muflie bor; 5G and is drawntherefrom through the valved intake passage 55 into the bore bil of thecompressor cylinder lil. cous refrigerant compressed in the cylinder 5lby the piston 1Q passes therefrom through the valved exhaust passagesinto an exhaust chamber l2@ formed in the inutile box 5d throng l aconduit E2G to an exhaust mufllerbl' and from there through a conduiti123.

rThe conduit U23, which is relatively horrible, being made of coppertubing or the like, is secured to a relatively heavy rigid support inorder to prevent vibration thereof. In the illustrative form of myinvention, the conduit H23 is soldered, or otherwise secured, Vasindicated at lilla in Figs. 2 and 5, to the periphery of the motor lli,thus providing a rigid mounting for the conduit 023.

secured inthis manner to the periphery of the motor l t, that is itextends about approximately one-sixth of the circumference of the motor.The conduit and muffler mounting described above is described andclaimed in my copending'divi-A4 sional application Serial No. 26,797 ledJune l5,

1935 and assigned to the General Electric Com= pany, the assignee of mypresent invention.

The lower portion of the conduitv H23 is helical in form, thus providinga resilient connection between the unitary compressor motor structurewhich is free to vibrate on the springs il), 2@ `and 2l and the rigidlymounted casing lll. lhe increased length of the conduit 23 so providedalso aids in dissipating the vibratory energy oi the compressed gaseousrefrigerant contained therein and hence in the suppression of noisecaused thereby. The compressed gaseous refrig= erant passes through aconduit l23 to a condenser ltd which is cooled by natural draft andwhich surrounds the casing l il being mounted on the annulus of heatconducting ns H2. Il'he com.`= pressed gaseous refrigerant is liquefiedin the condenser lZ and ows therefrom through a conduit W5, a flowcontrolling oat valve |26 and a conduit l2l to an evaporator |28. Theevaporator arcas-cs ze Gasit@ is supported in a cooling compartment onthe heat insulated removable top figc. The liquid refrigerant containedin the evaporator t28 is vaporized by the absorption of heat fromarticles contained in the cooling compartment in which the evaporator islocated and the refrigerant thus vaporized passes from the evaporatorl2@ through a suction conduit H29 baclr to the casing lll. lt will benoted that the disclmrge end t3@ oi the suction conduit i129 is locatedabove the normal level oi the lubricant @i2 in the reser voir formed inthe lower section l2 ci the casing l0. The vaporized refrigerant thusdischarged in the casing l@ is again drawn into the intake murder llland the cycle, above described, is repeated. It will be seen that thecasing [lll is normally lled with vaporized gaseous relrign 'erant abovethe level oi the lubricant till and any refrigerant which may have beenentrapped in the lubricant while the latr is passing through thecompressor i and the motor l@ will be re'- leased from the relativelyquiet body of lubricant and will be again mingled with the low pres=sure gaseous refrigerant thereabove.

'While have shown a particular embodiment ci my invention in connectionwith a compresH sion rerigerating machine, l do not desire my infavention to be limited to the particular construea tion shown anddescribed, and l intend inthe appended claims to cover all modicationswithin. the spirit and scope of my invention.

lhat l claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A refrigerating machine comprising a refrigerant compressor, aplurality of parts having contacting relatively moving surfaces, alubricant reservoir, means including a closed series lubricant circuitrorrecirculating lubricant `from said reservoir to said relativelymoving surfaces to lubricate the same, means connected in said serieslubricant circuit for controlling the loa/ding tor supplying lubricantto said relatively moving surfaces, means including a chamber having an.inlet and an outlet through which the lubricant flows continuously to,said moving surfaces and dependent upon a predetermined rate of ow oflubricant for loading said compressor when said lubricant is supplied tosaid relatively moving surfaces at a rate exceeding a predeterminedvalue,

,and means including a sharp edged orifice located at said outlet oisaid chamber for diverting a prem determined part of the lubricant fromsaid chamber to said compressor irrespective of the viscosity of thelubricant.

3. A refrigerating machine comprising a redetermined rate or" flow oflubricant for loadingY said compressor when said lubricant is suppliedto said compressor'at a rate exceeding a. prede- 75' termined value andfor unloading said compressor when said lubricant is supplied to saidcompressor and motor at a rate less than a predetermined value, andmeans including a sharp edged orifice located at said outlet of saidchamber for diverting a predetermined part of the lubricant from saidchamber to said compressor irrespective of the viscosity of thelubricant. L

4. A refrigerating machine comprising a refrigerant compressor, meansfor supplying lubri- -cant under pressure, means including a chamberaccumulating said lubricant supplied under pressure for controlling theloading of said compressor, means including a sharp-edged orificecontinuously diverting a predetermined part of the lubricant accumulatedin said chamber irrespective ofthe viscosity of said lubricant forlubricating said compressor, and means diverting an additional part ofthe lubricant accumulated in said chamber when the pressure thereinreaches a predetermined maximum.

5. A refrlgerating machine comprising a refrigerant compressor, anunloader cylinder, a piston movable in saidl unloader cylinder, lmeanssupplying lubricant under pressure to said unloader cylinder `foractuating said piston, means responsive to the movement of said pistonfor controlling the loading of said compressor, means including aconstantly open port in said cylinder and a sharp-edged orificeregisteringwith said port diverting a predetermined part oi thelubricant from said cylinder irrespective of the viscosity of saidlubricant for lubricating said compressor irrespective of' the positionof said piston in said unloader cylinder, and means diverting anadditional partA of the lubricant accumulated in said chamber when thepressure therein reaches a predetermined maximum for limiting themovement of, said piston.

6. A-refrigerating machine comprising a refrigerant compressor, a. motorfor driving said compressor, an unloader cylinder, apiston movable ,insaid unloader cylinder, means including 'a pump driven by said motor andsupplying lubril cant under pressure to said unloader cylinderjoractuating said piston, means responsive to the movement of said pistonforcontrolling the loading of said compressor, means including aconstantly open port in said unloader' cylinder and a sharp-edgedoriiice` registering with said port diverting la predetermined part ofthe lubricant :from said' cylinder irrespective of the viscosity to themovement of said piston for controlling the loading of said compressor,means for biasing said piston toward a positionl in which saidcompressor is unloaded, means including a constantly open port in saidunloader cylinder and a sharpedged orice registering with said portdiverting@ a predetermined part of the lubricant from said cylinderirrespective of the'visco'sity oi' the lubricant for lubricating saidcompressorirrespective of the position of said piston in said unloadercvlinder, and means diverting an additional part -of said piston.

of the lubricant accumulated in said chamber through said port when thepressure therein reaches a predetermined maximum for limiting themovement of said piston.

8. A refrigerating machine comprising a refrigerant compressor, anunloader cylinder, a piston movable in said cylinder, means supplyinglubricant under pressure .to said unloader cylinder for actuating saidpiston, means including a valve and responsive to the movement of saidpiston for controlling the loading of said com'-l pressor, means forbiasing said piston toward a position in which said compressor isunloaded, means including a constantly open port in said unloadercylinder and a sharp-edged orifice registering with said port diverting-a predetermined part of the lubricant from said cylinder irrespectiveof the viscosity of the lubricant for lubrieating said compressorirrespective of the position of said piston in said unloader cylinder,and

means diverting an additional part of the lubricant accumulated in saidchamber through said port when the pressure therein reaches apredetermined maximum for limiting the movement of said piston.

9. A refrigerating machine comprising a refrigerant compressor providedwith inlet and exhaust valves, an unloader cylinder, a piston movable insaid cylinder, means supplying lubricant under pressure to said cylinderfor actuating said piston, means responsive to the movement of saidpiston and engaging one of said valves of said compressor forcontrolling the loading of said compressor, means including a constantlyopen 4 port in said unloader cylinder and a sharp-edged orificeregistering with said port diverting a predetermined part of thelubricant from said cylinder irrespective of the viscosity of thelubricant for lubricating said compressor irrespective of the positionof said piston in said unloader cylinder, and means diverting anadditional part of the lubricant accumulated in said chamber throughsaid port when the pressure therein reaches a predetermined maximum forHunting the movement of said piston.

10. A refrigerating machine comprising a re`- frigerant compressorprovided with inlet and exnaustl valves, an unloader cylinder, a. pistonmovable in said unloader cylinder, means supplying lubricant underpressure to said cylinder for.

actuating said piston, means responsive to the movement of said pistonand engaging said inlet valves of said compressor for lcontrolling theloading ofk said compressor, means including a compression spring forbiasing said piston toward a position in which Isaid compressor isunloaded,

means including a constantlyopen port in said 'unloader cylinder and asharp-edged orifice registering with said port diverting a predeterminedpart ofthe lubricant -from said cylinder irrespective oi' the viscosityof the lubricant for lubrieating said compressor irrespective of theposition of said piston in said unloader cylinder, and means divertingan additional part of the lubricant accumulated in said chamber throughsaid port when the pressure therein reaches a predetermined maximum forhunting the movement i 11. A refrigerating machine comprising arefrigerant compressor provided with a compression cylinder, an inletvalve for said compre'ssion carried by said compressor and arrangedparallel tosaid compression cylinder and with one end cylinder locatedat one end thereof, a motor for.

driving said compressor, an unloader cylinder lil thereof adjacent saidinlet valve, a piston movable in said unloader cylinder, means includinga pump driven by said motor and supplying lubricant under pressure tosaid unloader cylinder Vfor actuating said piston, means including aU-shaped operating rod secured to said piston and operatively associatedWith said inlet valve for controlling the loading of said compressor,means'including a compression spring for biasing said operating rodtoward a position in which it holds said inlet valve open. meansincluding a constantly open port in lsaid unloader cylinder and asharp-edged orifice registering with said port diverting a predeterminedpart of the lubricant from said unloader cylinder for lubricating saidcompressor, irrespective of the position of said piston in saidfunloadercylinder, and means diverting an additional part of the lubricantaccumulated in Vsaid chamber when the pressure therein reaches apredetermined maximum for limiting the movement of said piston.

12. A refrigerating machine comprising a refrigerant compressor providedwith a compression cylinder, an inlet valve for said compressioncylinder located one end thereof, a motor for driving 'smd compressor,an unloader cylinder carried by said compression cylinder and arrangedparallel to said compression cylinder `with one end thereof adjacentsaid inlet valve, a piston movable in said uploader cylinder, meansincluding a pump driven by said motor and supplying lubricant underpressure to said uploader cylinder for actuating said piston, meansincludv ing a ll-shaped operating rod secured to said piston andoperatively associated with said inlet Y valve for controlling theloading of said compressor, and means including a compression spring forbiasing said operating rodv toward a position in which it holds saidinlet valve open.

13. A refrigerating machine comprising a refrigerant compressor, meanssupplying lubricant under pressure for lubricating said compressor,means for controlling the loading of said compressor in response to thepressure oi said lubricant, and means including a sharp edged orificefor causing said loading controlling means to be 'unresponsive tochanges in viscosity of said lubricant.

lll. A refrigerating machine comprising a reirigerant compressor, meanssupplying lubricant under pressure for lubricating said compressor,means including ay chamber accumulating said lubricant ier controllingthe loading and unload'- ing oi said compressor, means diverting part ofthe lubricant accumulated in said chamber for lubricating ,saidcompressor during loaded and unloaded operation thereof, and meansincluding a sharp edged orice for causing said loading and unloadingcontrolling means. to be unresponsive `yto changes in viscosity of saidlubricant.

l5. A reirigerating machine comprising a reirigerant compressor, anunloader cylinder, a pis= ton movable in -`said cylinder, meanssupplying lubricant under pressure to said cylinder for actuating saidpiston, means responsive to the A frigerant compressor provided withinlet and exhaust valves, an uploader cylinder, a piston cant from saidcylinder irrespective of the vls'- cosity ofthe lubricant forlubricating said compressor irrespective of the position of said pistonin said cylinder.

17. A refrigerating machine comprising a refrigerant compressor providedwith a compression cylinder, an inlet valve. for said compressioncylinder located'at one end thereof, a motor for driving saidcompressor, an unloader cylinder carried by said compressor and arrangedparallel to said compression cylinder, a piston movable in said unloadercylinder, means including a pump driven by said motor andsupplyinglubricant under pressure to said unloader cylinder for actuating saidpiston, Ymeans including a U- shaped operating rod secured to saidpiston and` operatively associated with said inlet valve for controllingthe loading of said compressor, means including a compression spring forbiasing said operating rod toward a position in which it holds saidinlet valve open, and means including a sharp edged oriiice in saidpiston and a constantly open port registering with said orice in saidpiston when said compressor is unloaded for diverting a predeterminedpart of the lubricant from said cylinder irrespective of the viscosityoi the lubricant for lubricating said compressor irrespective oi theposition of said piston in said cylinder.

i3. An unloading mechanism for a compressor or 'the like comprising achamber having a movable `Wall, means supplying an accumulation oi ingsaid movable Wall, means responsive to the movement of saidA movablewall under the inuence of said accumulation of liquid for controllingthe loading of a compressor, and means including a sharp edged oricehaving an unobstructed approach thereto for diverting a predeterminedportion of said accumulation of liquid from said chamber irrespective ofthe viscosity of the liquid. L

. lli. .ein unloading mechanism for a compressor or the likecomprisingan unloader cylinder, a

piston movable in said unloader cylinder, means supplying anaccumulation of fluid under pressure to said cylinder' for actuatingsaid piston, means responsive to the movement of said piston in saidcylinder under the influence of said fluid for controlling the loadingand unloading of a compressor, and means including a sharp edged oriiicediverting a portion of said accumulation oi duid from said cylinder forcausing said loading and unloading controlling means to lieVunresponsive to changes in the viscosity of said fluid.

2c. an unloading mechanism for a compressor or the like comprising anunloader cylinder, a piston movable in said unloader cylinder, meanssupplying an accumulation of iluid under pressure to said cylinder foractuating said piston,

means responsive to the movement of said piston for controlling theloading of a compressor, and

unobstructed approach thereto for diverting a predetermined portionofthe accumulation of liquid under pressure to said chamber foractuatlmeans including a sharp edged orice havlngan fluid from saidunloader cylinder irrespective of the viscosity of the fluid.

21. An unloading mechanism for a compressor or the like comprising acylinder provided with an outlet port in a side wall thereof, a pistonmovable in said cylinder and having a cylindrical portion extendingbeyond the head thereof and normally overlying said outlet port, meanssupplying an accumulationv of fluid under pressure to said chamber foractuating said piston, means responsive to the movement of said pistonfor controlling the loading of a compressor, and means including a sharpedged orifice formed in said cylindrical portion of said piston andregistering with said outlet port when said piston is in the unloadingposition for diverting a predetermined portion of the fluid accumulatedin said cylinder irrespective of the viscosity of the fluid.

22. A refrigerating machine comprising a refrigerant compressor providedwith a compression cylinder, an inlet valve for vsaid compressioncylinder located at one end thereof, a motor for driving saidcompressor, an unloader cylinder carried by said compressor and arrangedparailel to said compression cylinder, a piston movable in said unloadercylinder and having a cylindrical portion extending beyond the headthereof, means including a pump driven by saidy motor supplyinglubricant under pressure to said unloader cylinder for actuating saidpiston, means including a U-shaped operating rod secured to said pistonand operatively associated with said inlet valve for controllingtheloading of said' compressor, means including a compression spring forbiasing said operating rod toward a position in which it holds saidinlet valve open, and means including a. sharp edged orifice in thecylindrical portion of said piston and a constantly open port in saidcompression cylinder registering With said orifice when said piston isin the unloading position for diverting a predetermined part of thelubricant from-said cylinder irrespective of the viscosity of thelubricant and 'for lubricating said compressor irrespective of 'unloadsaid compressor and for maintaining said compressor unloaded until saidexcess of vaporizable refrigerant is removed from said lubricant. 24. Arefrigerating machine including a closed compression system containing avaporizable refrigerant and a-lubricant in direct contact, a

motor and a refrigerant compressor enclosed '1n quate lubrication forcausing said last mentioned means to unload said compressor and formain:-l

taining said compressor unloaded until said excess of vaporizablerefrigerant is removed from said lubricant.

25. A refrigerating machine including a closed compression systemcontaining a vaporizable refrigerant and a lubricant in direct contact,a motor and a refrigerant compressor in said system, said compressorbeing provided with inlet and exhaust valves, means supplying lubricantunder pressure for lubricating said compressor, Y

means to unload said compressor and for maintaining said compressorunloaded untilsaid excess of vaporizable-refrigerant is removed fromsaid lubricant.

26. A refrigerating machine comprising a refrigerant compressor, meansdependent upon the operation of said compressor for supplying a liquidunder pressure, means for controlling the `loading of said compressor inresponse to the pressure of said liquid, and means including a sharpedged orifice and an arrangement causing said liquid to flow through'said orifice for caus- HARLEY H. BIXLER.

